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DOE OSTI · 1803113

Low-spin cobalt(ii) redox shuttle by isocyanide coordination

Raithel, Austin L.·Kim, Tea-Yon·Nielsen, Karl C.·Staples, Richard J.·Hamann, Thomas W.
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Abstract

Coordination of the strong-field ligand 2,6-dimethylphenyl isocyanide (DMP-CN) to the Co(PY5Me 2 ) framework, where PY5Me 2 represents the pentadentate ligand 2,6-bis(1,1-bis(2-pyridyl)ethyl)pyridine, has resulted in a new low-spin Co(II) complex with a relatively low reorganization energy and fast electron-transfer kinetics compared to the prototypical cobalt tris-bipyridine redox shuttle, [Co(bpy) 3 ] 3+/2+ , where bpy represents 2,2'-bipyridine. Despite nearly 160 mV reduced regeneration driving force, the [Co(PY5Me 2 )(DMP-CN)]3+/2+ redox shuttle displayed an increased regeneration efficiency relative to [Co(bpy)3] 3+/2+ , however recombination losses hinder the performance as evidenced by a reduced recombination resistance. Finally, future directions point to low-spin Co(II) redox shuttles with more negative redox potentials to be paired with a dye or dye mixture that absorbs into the near infrared region.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYchemistrycobalt complexdye-sensitized solar cellsenergy & fuelslow-spinmaterials scienceredox shuttle

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Raithel, Austin L., Kim, Tea-Yon, Nielsen, Karl C., Staples, Richard J., Hamann, Thomas W.. 2020-03-09. Low-spin cobalt(ii) redox shuttle by isocyanide coordination. https://doi.org/10.1039/d0se00314j

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